Romans 9:7
and they are not all the children of Abraham because they are his descendants [by blood], but [the promise was]: “Your descendants will be named through Isaac” [though Abraham had other sons].
Genesis 21:12
God said to Abraham, “Do not let it distress you because of Ishmael and your maid; whatever Sarah tells you, listen to her and do what she asks, for your descendants will be named through Isaac.
Hebrews 11:18
to whom it was said, “Through Isaac your descendants shall be called.”
Luke 3:8
Therefore produce fruit that is worthy of [and consistent with your] repentance [that is, live changed lives, turn from sin and seek God and His righteousness]. And do not even begin to say to yourselves [as a defense], ‘We have Abraham for our father [and so our heritage assures us of salvation]’; for I say to you that from these stones God is able to raise up children (descendants) for Abraham [for God can replace the unrepentant, regardless of their heritage, with those who are obedient].
Luke 16:24-25
Luke 16:30
John 8:33
They answered Him, “We are Abraham’s descendants and have never been enslaved to anyone.
John 8:37-39
Galatians 4:23
But the child of the slave woman was born according to the flesh and had an ordinary birth, while the son of the free woman was born in fulfillment of the promise.
Philippians 3:3
for we [who are born-again have been reborn from above—spiritually transformed, renewed, set apart for His purpose and] are the true circumcision, who worship in the Spirit of God and glory and take pride and exult in Christ Jesus and place no confidence [in what we have or who we are] in the flesh—